[Wannier] Convergence of MLWFs

[Carlo Motta]

Dear wannier90 users,

I am a new user and I am trying to calculate the MLWFs for the (HOMO, HOMO-1) bands of a a molecular crystal with 2 molecules per unit cell.
My problem is that I see instabilities in my results, in particular in the matrix elements in the durene_hr.dat.  
I did convergence tests wrt the k-mesh and cutoff energy. The durene_hr.dat values are crazy (no regularity with respect to the convergence parameter).
I have checked that the wannierization has converged, since the Delta values are below 1E-7. 

My beginning projections are random, since I have no clue on how to improve it for this large system. 
Having 2 molecules in the unit cell, whose centers in crystal coordinates are 0.0,0.0,0.0 and 0.0,0.5,0.5, I tried to do this:
    begin projections
    c=0.0,0.0,0.0:l=0
    c=0.0,0.0,0.0:l=0
    c=0.0,0.5,0.5:l=0
    c=0.0,0.5,0.5:l=0
    end projections
but the results are even worse (not converged).
However, I am conscious that putting an s orbital (l=0) in the center of mass of the molecules as a starting guess does not make much sense.

Probably I have still some parameter in my calculations that is still not at convergence. Which are the ones most influencing the wannierization?
Is there a possibility to run a wannierization by starting from the solution found in a previous calculation? I am asking this also because in different calculations, the labels of the different WFs (1, 2, 3,...) mix up.

If you need more informations I will provide them!

Thank you in advance,

Carlo

--

Carlo Motta,

PostDoc Researcher
School of Physics and CRANN,          IE Mob.: +353 (0) 83440 8930
Trinity College Dublin,                          IT Mob: +39 3286845055
Dublin 2, IRELAND